Protecting alarm-circuit



(No Model.)

I. E. BARRICLOW.

PROTECTING ALARM CIRCUIT.

No. 591,725. Patented Oct. 12,1897.

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UNITED STATES PATENT OFFICE.

IRVIN E. BARRI CLOW, OF DALLAS, TEXAS.

PROTECTING ALARM -C|RCU|T.

SPECIFICATION formingpart of Letters Patent No. 591,725, dated October 12, 1897. Application filed June 22, 1896. Serial N- Q6,506. (N0 model.)

To wZZ whom it may concern:

Be it known that I, IRVIN E. BARRIOLOW, a citizen of the United States, and a resident of Dallas, in the county of Dallas and State of Texas, have invented certain new and useful Improvements in Protecting Electric Alarm-Circuits, of which the following is a specification.

The object of my invention is to protect a place or an object by means of an electric circuit so applied and combined with an alarm and other apparatus that the protected place or object cannot be broken into or the protecting-circuit broken or short-circuited without giving an alarm at the alarm-station.

In putting my invention into effect I employ an alarm device or other suitable indicator held normally inoperative by two bal anced powers, either of which actuates the alarm or indicator in the event of the other losing power or in the event of gaining power itself. One of these balanced powers is an electromagnet, while the other may be a spring or any equivalent device, and an arm or other moving part arranged to actuate the alarm by movement in either of two directions is brought under control of these two balanced powers and by them normally held in an intermediate position. The electromagnet constituting one of these powers is included in the line-circuit to be protected, and means is employed for maintaining a constant current on this line-circuit. In order to prevent tampering with the line-circuit, this currentcontrolling resistance is duplicated, one resistance being located at the local station and the other at the distant point to be protected, and pole-changers are employed adjacent to the respective resistances in order to introduce them alternately in the line-circuit, so that while the effect on the electromagnet is the same as if one resistance remained in all the time it is obvious that should the line be tampered with the distant resistance, which is of known length and equal to the local resistance, will fail to do its duty and the equilibrium which holds the alarm inactive will be destroyed.

In addition to the foregoing features my invention consists in novel details in the arrangement of the parts and current-rovers:

ing apparatus, as will hereinafter be fully described, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a diagrammatic view illustrating the complete system. Figs. 2, 3, and 4. are detail views showing, respectively, the two polechangers and the commutator on the local pole-changer, vwhich reverses the current on the line and actuates the distant pole-changer.

1 represents the alarm, which may be in the form of an ordinary electric bell and un* der control of a circuit composed of the wires 2 3 4 and including a battery 5, two contactpoints 6 7, and an arm 8, pivoted at 9 and vibrating betweenthe contacts 6 and 7. Upon the pivot 9 of the arm 8 is mounted a spring 10, which tends to swing said arm against the contact 7,, and also an armature 11, which is under the influence of the poles 12 of electromagnet 13 and tends to swing the arm 8 against contact 6.

14 is an arm by means of which the tension of the spring may be regulated at will.

15, 16, and 17 represent the local wires of the line-circuit, which includes the electromagnet 13 and a local standard battery 18. These wires also connect with a pole-changer 20 at the local station and through it with the main-line wires 21 and 22, which lead to the distant point to be protected.

23 23 represent a network of conductors forming a part of the main line and forming a cover and a lining to the inclosure for parts of the. system which are located at the distantpoint, and this network of conductors is such that the inclosure cannot be tampered with'without breaking the circuit, which fact will be immediately indicated at the local station.

24: is a inclosure.

In order to maintain a constant current over the line 15, 16, 17, 21, and 22 and through magnet 13, a local resistance 25 is employed, which, together with the standard battery 18, will serve this purpose. In order that it may pole-changer within the protected be known at all times whether the distant protected point remains undisturbed and in circuit,.a precisely similar resistance 25 is located at said distant point, and these resistances 25 and 25 are connected by shuntwires 26 27 and 26 27 and the pole-changers and 24 are arranged to operate synchronously and alternately introduce these resistances into the line-circuit. If, therefore, the distant resistance should not be regularly interposed and withdrawn from the line at the proper time, or if an attempt should be made to introduce some other resistance not precisely the equivalent of the local resistance 25, the equilibrium between electromagnet 13 and the spring 10 would be destroyed and the alarm set in operation. The same effect would be produced if any accident should take place.

The distant pole-changer 24 is actuated by the local pole-changer 20, and in order that the local pole-changer '20 may produce the necessary alternations in the circuit 21 22 and simultaneously cut in and out the local resistance 25 said pole-changer consists, preferably, of a permanent magnet 28 and an electromagnetic armature 30, carrying commutator plates 30, 31, and 32. Contactbrushes 33 and 34 bear alternately upon the plate 29 and upon one of the plates 31 and 32. Now since the wire 21 is connected with the plate 30 and the wires 22 and 26 are connected, respectively, with the plates 31 and 32 it is obvious that the current from battery 18 as supplied by wires 15 and 17, connected, respectively, with brushes 33 and 34, will be of the line-circuit represented by wires 21 and 22, and simultaneously with these alternations the resistance 25 will be switched in and out. The distant pole-changer 24 comprises permanent magnet 35 and electromagnetic armature 36, included in the line-circuit, and by means of contact-pins 37 38, connected through the medium of armature 36 and outside network 23 with the wire 22, and the contact-brushes 39 and 40, connected, respectively, with resistance 25 and the wire 21 through medium of inside network 23 the resistance 25 is switched in and out in continuous operation. Moreover, from the position of the parts as shown it will be observed that one of the resistances is switched in while the other is cut out.

It remains only to provide actuating means for the combined pole-changer and currentreverser 20. This consists of a clockwork 41 or other equivalent constantly-movin g mechanism having a vibrating arm 42, which is connected by a wire 43 with one end of electromagnetic armature 29, the other end of which is connected by wire 44 with an intermediate point 45 of the battery 5, hereinbefore referred to. Contacts 46 47 are connected by wires 48 49 with the opposite poles of said battery 5. If arm 42 rests in the position against contact 46,the current from battery 5 passes to armature 29, which-is thereby made to assume the position in which it is shown. By said armature the resistance 25 is cut out and current is directed from battery 18 over the line in the direction shown by featherless arrows, and the pole-changer ered arrows over the distant line 21 22.

24 assumes the position in which it is shown with the resistance 25 switched in. The electromagnet 13 gains no advantage nor is overcome by spring 10 and the alarm remains inactive. When the arm 42 passes to the position shown by dotted lines, the current is reversed through armature 29 and passes in the direction of feathered arrows. The armature is also reversed so as to bring contact-plate 29 beneath brush 34 and plate 32 on brush 33 when the resistance 25 is switched'in. The current is reversed in the direction of featsh- 1- multaneously armature 36 is shifted and resistance 25 is cut out.

From the foregoing description it will be understood that as the arm 42 is carried upon the balance-wheel of a clock mechanism it withdrawn from the line-circuit synchro Therenously and in continuous operation. fore the state of equilibrium of the alarmactuating device 13 remains undisturbed; but as both resistances and pole-changers must cooperate to maintain this balance it is obvious that any interference with the line Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. In a device for protecting electric circuits, the combination of a suitable alarm, an

i would result in sounding the alarmapparatus. alternated in direction over the distant part electromagnetic device controlling said alarm and arranged to be held normally inoperative by a current of certain intensity, a circuit including both the alarm-actuating device and the distant object to be protected polechangers located in said circuit at the station and at the distant object respectively, resistances adjacent to the respective pole-chang- IIO ers and adapted to be alternately introduced into the said circuit, and means for actuating the pole-changers synchronously as and for the purposes set forth.

2. In a device for protecting electric circuits, the combination of an alarm or equivalent indicator, a normally open circuit controlling same, a circuit-closer interposed in said alarm-circuit, an electromagnet combined with said circuit-closer so as to keep the same normally open but permit it to close upon a change taking place in the current .passing through said magnet, a line-circuit including said electromagnet and leading to the distant point to be protected, a resistance arranged in shunt with said line-circuit, a pole-changer having a local circuit for actuating it and combined with the line-circuit in such manner as to reverse the current therethrough and to simultaneously cut in and out the resistance arranged in shunt therewith,

, a pole-changer located at the distant point to be protected and actuated by alternations on the line-circuit, and a resistance at said dis tant point alternately cut in and out by said pole-changer; the pole-changers being synchronous in action and the two resistances being equal and introduced alternately into the line-circuit as explained.

3. In a device for protecting electric circuits, the combination of an alarm device or indicator held normally inactive by a current of constant measure and duplicate sets of apparatus located respectively at the alarm-station and at the distant point to be protected and each comprising a resistance, contacts for cutting said resistance alternately in and out and synchronously but oppositely vibrating circuit-closers moving back and forth between the two contacts, to alternately effect changes in the line-circuit in continuous operation, such changes being the same in character and together maintaining the constancy of the current which controls the alarm device.

4. In a device for protecting electric circuits, the combination of an indicator held normally inactive by a constant current over the circuit to be protected, and means for detecting interference with said circuit consisting of two resistances located respectively at the indicator-station and at the distant point, a pole-changer at the distant station for alternately cutting in and out the resistance there, a pole-changer at the indicator-station for cutting in and out the resistance there alternately with the resistance at the distant station, and also simultaneously reversing the current over the line -circuit, a clockwork or equivalent mechanism having a constantly-vibrating part, wires connecting the respective ends of the local pole-changer with the middle pointof a battery and with the constantly-vibrating part, and contacts cooperating with said vibrating part and connected respectively with the opposite poles of said battery, substantially as and for the purposes set forth.

IRVIN E. BARRICLOW.

Witnesses:

Enw. HIRSH, O. B. LINN. 

